Glass Knife Adapter for Cutting Epoxy Sections on a Conventional Rotary Microtome

Electron microscopy-style fixation followed by epoxy plastic embedding is often now the method of choice for preparing tissue even for light microscopy; I have found it excellent for fluorescence, autoradiographic and conventional histology (Shaw 1972, 1977). Sections more than about five microns thick can be cut on a really sharp steel knife if the plastic is reasonably soft (Stretton and Kravitz 1973, Shaw 1972), but this is much easier and knife marks are reduced if extra-wide glass knives are used on a special-purpose intermediate microtome like the Sorvall JB-4. Recent budgetary restrictions made us defer purchase of such a microtome, and some alternative had to be devised. I report here a simple but rugged adapter for glass knives which replaces the steel knife in a conventional Leitz rotary microtome and allows thin plastic sections to be cut as easily as with a more sophisticated cutter. It could be adapted for any rotary microtome, and can be readily constructed in most machine shops for negligible cost.